This disclosure relates generally to diagnostic imaging and, more particularly, to an improved packaging design for a computed tomography (CT) detector assembly.
Typically, in computed tomography (CT) imaging systems, an x-ray source emits a fan or cone-shaped beam toward a subject or object, such as a patient or a piece of luggage. Hereinafter, the terms “subject” and “object” shall include anything capable of being imaged. The beam, after being attenuated by the subject, impinges upon an array of radiation detectors. The intensity of the attenuated beam radiation received at the detector array is typically dependent upon the attenuation of the x-ray beam by the subject. Each detector element of the detector array produces a separate electrical signal indicative of the attenuated beam received by each detector element. The electrical signals are transmitted to a data processing system for analysis which ultimately produces an image.
Generally, the x-ray source and the detector array are rotated about the gantry within an imaging plane and around the subject. X-ray sources typically include x-ray tubes, which emit the x-ray beam at a focal point. X-ray detectors typically include a collimator for collimating x-ray beams received at the detector, a scintillator for converting x-rays to light energy adjacent the collimator, and photodiodes for receiving the light energy from the adjacent scintillator and producing electrical signals therefrom. Typically, each scintillator of a scintillator array converts x-rays to light energy. Each scintillator discharges light energy to a photodiode adjacent thereto. Each photodiode detects the light energy and generates a corresponding electrical signal. The outputs of the photodiodes are transmitted to the data processing system for image reconstruction. Imaging data may be obtained using x-rays that are generated at a single polychromatic energy. However, some systems may obtain multi-energy images that provide additional information for generating images.
The detector array (or assembly) and the x-ray tube are structurally mounted to the gantry. Generally, several issues can impact performance of the detector array. For instance, recent detector array designs include 3000 or more ASIC's that run at the same frequency, and can therefore cause electromagnetic interference (EMI). Also, detector assemblies include photodiodes that are light sensitive, which can lead to problems if there is external light exposure. Additionally, detector assemblies are often replaced in the field due to exposure to liquids that may include medical fluids, x-ray tube oil spills, and the like. The detectors are also subject to electrical problems if a ground loop is formed.
To mitigate such problems, detectors are designed to deal with each issue individually. For instance, multiple individual seals may be provided for detectors to reduce fluid contamination. However, overall the detector assembly is subject to EMI interference, light pollution, fluid contamination, and the like.
Therefore, it would be desirable to have a method and apparatus to collectively mitigate these issues.